The use of bladders as gas and liquid contents containers and propellants in aerosols is becoming more common, particularly since commonly used fluorochloro-carbon and other volatile propellants have been shown to be harmful to the environment, including causing damage to the ozone layer of the earth. Such bladders are commonly filled by an awkward process utilising special valves supplied by the bladder manufacturers. A need has existed for some time for a bladder mechanism which can be used by all aerosol manufacturers with existing standard equipment and which can be used on any bladder and any aerosol can. Such a mechanism should be sufficiently versatile that it can be used in the aerosol container production line for either "under the cap" filling or for "through the valve" filling.
Until recently, aerosols during manufacture were pressurised by injecting the propellant through the valve nozzle mounted at the top of the aerosol. This is a slow and inefficient process. Latterly, a more efficient "under the cap" process has been developed for rapidly filling aerosols on an assembly line with both working fluid and propellant in a pressurised environment. On the production line, the cap and nozzle of the aerosol are temporarily lifted under a pressurized filler head which fits on the top of the container and the contents and propellant are injected directly into the container, rather than through the valve. Unfortunately, this more modern efficient filling procedure has not been available for filling bladder powered aerosols. Such aerosols continue to be inefficiently filled "through the valve".
In recent years, there has been alarming evidence that the protective ozone layer of the earth is shrinking in thickness. The ozone layer is critical to the health of living organisms inhabiting the earth because the ozone layer filters out deadly ultra-violet rays, and other rays, emitted by the sun. Considerable evidence has been gathered to demonstrate that the damage that is occurring to the ozone layer is caused by a number of mankind generated free radicals and flurochlorocarbon-type propellants which have been used in aerosol container spray systems for many years. These propellants are lighter than the lower atmosphere and ascend to the elevation of the ozone layer. Chemical reactions then take place between the radicals and the ozone in the ozone layer thereby forming other compounds and complexes. This diminishes the free ozone in the ozone layer. There has been recent evidence to indicate that deadly holes have appeared in certain portions of the ozone layer, for example, over Antarctica. If this trend continues, the health of all living beings on the earth will be jeopardized.
Recently, industrialized nations of the world have agreed to an international moratorium on the use of substances which have been demonstrated to have a destructive effect on the ozone layer of the earth. In 1987, the United States enacted sunset-type legislation which forces companies that are manufacturing substances which are demonstrated to have a destructive effect on the ozone layer to phase out production of such harmful substances over a specified number of years. One of the most ozone layer destructive family of substances being manufactured are fluorochlorocarbons (Freons), which are widely used as coolants in refrigeration systems, and as propellants in aerosol spray containers holding products such as hair spray, cleaning compounds, and the like.
Because of the mounting evidence that fluorochlorocarbon propellants, and similar type volatile propellants, in aerosol contained spray systems, have a cumulative damaging effect on the ozone layer, it is critical to the long term health of living beings on the earth to develop alternative aerosol generating containers which do not rely upon ozone destroying propellants. As an alternative, many aerosol-type consumer products recently introduced on the market utilize a manual pump-type aerosol spray generating system. However, such manually operated aerosol pump systems are not entirely satisfactory because they are incapable of generating a fine consistent spray similar to the type that is generated by an aerosol container employing a fluorochlorocarbon propellant.
A number of patents have been granted in recent years for aerosol generating pump systems, and the like. These are useful as alternatives to volatile propellant aerosol generating sytems. U.S. Pat. No. 3,993,069, granted Nov. 23, 1976, Buckles et al., for example, illustrates a pumping system which utilizes a natural rubber bladder which is inflated. This inflated bladder generates pumping action from the force that is created by the bladder seeking to return to its original size and shape.
U.S. Pat. No. 4,222,499, granted Sep. 16, 1980, Harold D. Lee et al., discloses an apparatus for pressurized dispensing of fluid products comprising an elastomeric pressure unit, a support, a sealing member, and a valve. The apparatus may additionally include either a container for a housing around the pressure unit or a liner within the pressure unit. The elastomeric pressure unit has an internal cavity which contains the fluid product and provides the dispensing pressure. An assembly of such an apparatus is obtained without bonded connection and without the requirement of an additional sealing member when a liner is used. Lee et al employ a through the valve filling technique.
U.S. Pat. No. 4,324,350, granted Apr. 13, 1982, Kenneth W. Thompson, discloses a unitary, self-contained fluid spray dispenser comprising an elongated tubular expandable unit of elastomeric material of selected diameter and length. It is attached at its open end by a bonding agent to a valve support plate by way of a plastic neck piece carried by the open end of the unit. The expandable unit is filled with fluid to be dispensed through the valve and is distended to a selected volume and internal pressure. A housing of various materials can be implemented to carry the dispenser for purposes of convenience, handling and appearance.
U.S Pat. No. 4,121,737, granted Oct. 24, 1978, Calvin L. Kain, discloses an apparatus for pressure dispensing fluid products. The apparatus has an elastomeric pressure unit disposed in surrounding relationship to a flexible, fluid-tight liner. The liner has its open end sealably engaged with a valve support and a dispensing valve therein. The inherent elastomeric contracting force provides the dispensing pressure for the product contained within the flexible liner. The liner prevents contact between the product and the elastomeric material of the pressure unit.
U.S. Pat. No. 3,961,725, granted June, 1976, Clark, discloses an aerosol power system utilizing a bladder with a liner. The liner is indicated to be of a non-elastomeric material. There is no disclosure in this patent of using the liner and the outer bladder in combination as a power system.
None of the aforementioned patents disclose the concept of two or more concentrically arranged bladders which contribute a cumulative propulsion force in expelling contents from the container through the nozzle. Also none of the noted patents show a clamp which can be used in an aerosol container to permit under the cap filling and which enables two or more bladders to be secured to the nozzle and valve assembly of the aerosol container.